Abstract: An electric discharge machine and an electric discharge machining method for the electric discharge machine are provided. The electric discharge machine includes a circulation pump for pressure-feeding a work fluid in a dirty fluid tank to a filter; a jetting pump for pressure-feeding the work fluid in the clean fluid tank to a jetting nozzle; a feeding pump for pressure-feeding the work fluid in the clean fluid tank to the work tank; and a pump controller for inverter-controlling the circulation pump, the jetting pump, and the feeding pump. The pump controller includes a jetting pump controller configured to set an inverter frequency of the jetting pump, and a feeding pump controller configured to acquire the flow rate of the inverter-controlled jetting pump and set an inverter frequency of the feeding pump based on the flow rate of the inverter-controlled jetting pump.

Abstract: A compact lower guide unit that allows the electrode guide to be attached and detached more easily and reliably. Provided is a lower guide unit including a housing, an electrode guide, and a pull-up mechanism having a guide support, links, and a power cylinder. The guide support includes a biasing member and a displacement member. The biasing member can bias the displacement member, and the displacement member can be displaced between a restriction position and a release position. The links can be rotated by a force applied by the power cylinder. The electrode guide is fixed to the guide support by a biasing force of the biasing member when the displacement member is in the restriction position, and the electrode guide is released from the lower guide unit when the displacement member is displaced to the release position.

Abstract: An electric discharge machining unit capable of stably supplying working fluid to the vicinity of a portion to be machined. The electric discharge machining unit includes a tool electrode, a housing, an electrode guide, and a working fluid supplying device. The housing includes a fitting hole having a tapered surface. A first supply path is formed in the housing. The electrode guide includes a tapered portion and an ejection opening formed on a lower surface. A first flow path is formed in the electrode guide. The tapered portion is configured to be fitted into the fitting hole to connect the first flow path to the first supply path. The working fluid supplied from the working fluid supplying device to the first supply path and the first flow path is ejected from the ejection opening.

Abstract: A change device, a fine hole electric discharge machine, and an electrode change method that enable automatic and continuous machining of a large number of holes using electrodes of different diameters. A fine hole electric discharge machine including automatic electrode supply devices and a first change device is provided. The automatic electrode supply device includes an electrode cartridge storing a plurality of electrodes of a predetermined diameter and an electrode feeder device supplying the electrodes one by one from the electrode cartridge. The first change device includes a first magazine accommodating the automatic electrode supply devices in a detachable manner and a first transfer device transferring the automatic electrode supply device between the first magazine and a first chuck on a machining main spindle. The first magazine accommodates a plurality of automatic electrode supply devices storing the electrodes of different diameters.

Abstract: A compact lower guide unit that allows the electrode guide to be attached and detached more easily and reliably. Provided is a lower guide unit including a housing, an electrode guide, and a pull-up mechanism having a guide support, links, and a power cylinder. The guide support includes a biasing member and a displacement member. The biasing member can bias the displacement member, and the displacement member can be displaced between a restriction position and a release position. The links can be rotated by a force applied by the power cylinder. The electrode guide is fixed to the guide support by a biasing force of the biasing member when the displacement member is in the restriction position, and the electrode guide is released from the lower guide unit when the displacement member is displaced to the release position.

Abstract: An electric discharge machining unit capable of stably supplying working fluid to the vicinity of a portion to be machined. The electric discharge machining unit includes a tool electrode, a housing, an electrode guide, and a working fluid supplying device. The housing includes a fitting hole having a tapered surface. A first supply path is formed in the housing. The electrode guide includes a tapered portion and an ejection opening formed on a lower surface. A first flow path is formed in the electrode guide. The tapered portion is configured to be fitted into the fitting hole to connect the first flow path to the first supply path. The working fluid supplied from the working fluid supplying device to the first supply path and the first flow path is ejected from the ejection opening.

Abstract: A wire electric discharge machining apparatus is provided to equip with an automatic wire threader more reliably threading a wire electrode through an start hole. The wire electric discharge machining apparatus includes an automatic wire threader including: a feed roller disposed higher than the start hole and feeding a wire electrode toward the start hole; and a vertical drive device disposed between the feed roller and the start hole, and supplying compressed air in the upward and downward directions to vertically move the wire electrode slightly. The vertical drive device includes wire guides having guide holes through which the wire electrode is passed. The wire guides are constructed so that upward movement by the compressed air is possible.

Abstract: Disclosed is a method for recovering a corrosion preventive agent in an electrodischarge machining liquid supply apparatus. The method includes the step of passing a first electrodischarge machining liquid having a corrosion preventive agent added there to through, an ion exchange resin column to maintain a suitable specific resistance of the first liquid, and the step of passing a second liquid free from a corrosion preventive agent through the ion exchange resin column to desorb the corrosion preventive agent adsorbed in the ion exchange resin column. The second liquid is, for example, tap water or a machining liquid having a low corrosion preventive agent concentration. The corrosion preventive agent is, for example, adenine which is a purine base.

Abstract: A wire electric discharge machining apparatus is provided to equip with an automatic wire threader more reliably threading a wire electrode through an start hole. The wire electric discharge machining apparatus includes an automatic wire threader including: a feed roller disposed higher than the start hole and feeding a wire electrode toward the start hole; and a vertical drive device disposed between the feed roller and the start hole, and supplying compressed air in the upward and downward directions to vertically move the wire electrode slightly. The vertical drive device includes wire guides having guide holes through which the wire electrode is passed. The wire guides are constructed so that upward movement by the compressed air is possible.

Abstract: Disclosed is a method for recovering a corrosion preventive agent in an electrodischarge machining liquid supply apparatus. The method includes the step of passing a first electrodischarge machining liquid having a corrosion preventive agent added there to through, an ion exchange resin column to maintain a suitable specific resistance of the first liquid, and the step of passing a second liquid free from a corrosion preventive agent through the ion exchange resin column to desorb the corrosion preventive agent adsorbed in the ion exchange resin column. The second liquid is, for example, tap water or a machining liquid having a low corrosion preventive agent concentration. The corrosion preventive agent is, for example, adenine which is a purine base.

Abstract: A combined machining apparatus (2) includes a work stand (18) for fixing a workpiece (4), a jet nozzle (6) for jetting high pressure water towards the workpiece, a wire electrode (8), and upper and lower wire guides for supporting the wire electrode perpendicularly. The jet nozzle and upper wire guide are capable of being moved between an operating position where the workpiece can be cut and a respective refuge position separated from the operating position. The workpiece fixed to a work stand is cut to a desired shape by water jet cutting, and the cut surface is then finished to desired high machining accuracy using wire electric discharge machining with the workpiece still fixed to the work stand.

Abstract: A small hole electric discharge machine for forming a small hole in a workpiece by generating electric discharge between a rotating elongate pipe electrode (49) having a diameter of 1.0 mm or less and the workpiece. The small hole electric discharge machine may contain a column (11), a W-axis slider (21, 23) attached to the column so as to be moveable in the direction of a vertical W-axis, a Z-axis slider (31) attached to the W-axis slider so as to be moveable in the direction of a vertical Z-axis, a machine head (40) attached to the Z-axis slider the pipe electrode being attached to the machine head, a linear motor (90) for moving the Z-axis slider, and a gas spring (50) for generating a balance force to counteract the gravitational force acting on the Z-axis slider.

Abstract: A small hole electric discharge machine for forming a small hole in a workpiece by generating electric discharge between a rotating elongate pipe electrode (49) having a diameter of 1.0 mm or less and the workpiece. The small hole electric discharge machine comprises a column (11), a W-axis slider (21, 23) attached to the column so as to be moveable in the direction of a vertical W-axis, a Z-axis slider (31) attached to the W-axis slider so as to be moveable in the direction of a vertical Z-axis, a machine head (40) attached to the Z-axis slider the pipe electrode being attached to the machine head, a linear motor (90) for moving the Z-axis slider, and a gas spring (50) for generating a balance force to counteract the gravitational force acting on the Z-axis slider.